package com.leoman.utils;

import com.leoman.entity.Configue;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * Created by Administrator on 2016/9/2 0002.
 */
public class HttpImageUtil {
    /**
     * 测试
     *
     * @param args
     */
    public static void main(String[] args) {
        String url = "http://www.baidu.com/img/baidu_sylogo1.gif";
        /*byte[] btImg = getImageFromNetByUrl(url);
        if (null != btImg && btImg.length > 0) {
            System.out.println("读取到：" + btImg.length + " 字节");
            String fileName = "百度.gif";
            writeImageToDisk(btImg, fileName);
        } else {
            System.out.println("没有从该连接获得内容");
        }*/
    }

    /**
     * 将图片写入到磁盘
     *
     * @param img      图片数据流
     * @param fileName 文件保存时的名称
     */
    public static void writeImageToDisk(byte[] img, String fileName) {
        try {
            File file = new File(Configue.getUploadPath() + fileName);
            FileOutputStream fops = new FileOutputStream(file);
            fops.write(img);
            fops.flush();
            fops.close();
            System.out.println("图片已经写入到硬盘");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 根据地址获得数据的字节流
     *
     * @param strUrl 网络连接地址
     * @return
     */
    public static byte[] getImageFromNetByUrl(String strUrl) {
        try {
            //new一个URL对象
            URL url = new URL(strUrl);
            //打开链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            //设置请求方式为"GET"
            conn.setRequestMethod("GET");
            //超时响应时间为5秒
            conn.setConnectTimeout(5 * 1000);
            //通过输入流获取图片数据
            InputStream inStream = conn.getInputStream();
            //得到图片的二进制数据，以二进制封装得到数据，具有通用性
            return readInputStream(inStream);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 从输入流中获取数据
     *
     * @param inStream 输入流
     * @return
     * @throws Exception
     */
    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        //创建一个Buffer字符串
        byte[] buffer = new byte[1024];
        //每次读取的字符串长度，如果为-1，代表全部读取完毕
        int len;
        //使用一个输入流从buffer里把数据读取出来
        while ((len = inStream.read(buffer)) != -1) {
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
            outStream.write(buffer, 0, len);
        }
        //关闭输入流
        inStream.close();
        //把outStream里的数据写入内存
        return outStream.toByteArray();
    }
}
